2nd Nine Weeks Exam Life Science

a new organism begins to form when egg and sperm join in a process called:

fertiliation

what is the passing of physical characteristic from parents to offspring

heredity

what carries amino acids to the ribosomes and adds them to the growing protein chain

transfer RNA (tRNA)

the process in which the number of chromosomes is reduced by half to form sex cells is known as:

meiosis

the scientific study of heredity is known as

genetics

each characteristic of a different form is known as

trats

when an organism is the offspring of many generations that have the same trait it is known as

purebred

what did Gregor Mendel study in order to understand the process of heredity

pea plants

when Mendel crossed purebred tall pea plants and purebred short pea plants - all of the offspring where:

tall

in _______________ the alleles are neither dominant nor recessive - as a result, both alleles are expressed in the offspring

codominance

an organism with heterozygous alleles (Bb) is known as:

hybrid

an organism’s genetic makeup or allele combination is known as:

genotype

an organism with two identical alleses for a trait is said to be:

homozygous

an organism’s physical appearance of visible traits is known as:

phenotype

a number or percent that describes how likely it is that an event will occur

probability

a chart that shows the possible outcomes of alleles that can result from a genetic cross

Punnett square

only offpsring that inherit two recessive alleles will have:

the recessive trait

the different forms of a gene are known as

alleles

how are RNA and DNA different?

1-RNA is single stranded and uses the sugar ribose

2 - DNA is double stranded and uses the sugar deoxyribose

when using probability, do the reslts from previous results impact the results of the next test?

NO

T/F if both parents present (phenotype) a dominant trait, their offspring cannot present in the recessive trait:

false Both parents can carry recessive alleles.

T/F a dominant allele can be represented by two genotypes (mother and father)

false

an example human trait is controlled by a single gene with multiple alleles:

blood type

T/F a widow’s peak is a human trait controlled by a single gene

true

T/F a genome is all the DNA in one cell of an organism

TRUE

the rate of decay of a radioactive element is measured by its:

half life

T/F according to the theory of punctuated equilibria, evolution occurs slowly but steadily

false

what is meant by the term extinct?

all members of a species have died

which is less likely to become a fossil? WHY?

soft bodied organisms - they break down too fast b/c they have no shells, teeth, or bones

T/F the technique of relative dating can be used to determine the actual age of a fossil:

false

T/F Darwin’s idea baout how evolution occurs is called natural selection

true

T/F a diagram that shows how organisms might be related is called gradualism:

false

fossils formed when an organism dissolves and leaves an empty space are called

molds

similar structures that related species have inherited from a common ancestor are called

homologous structure

a trait the helps an organism survive and reproduce is called:

adaptation

why is there a wde variety of phenotypes for skin color in humans?

skin color is controlled by multiple genes

T/F hybridization is the crossing of two genetically similar organisms

false

T/F a karyotype tracks which members of a family have a trait

false

T/F a male inherits two X chromosomes

false

an organism that hs the same genes as the organisms from which it was produced

clone

which would most likely be used to diagnose Down Syndrom?

karyotype

a sex-linked disorder is:

color blindness / hemophilia

insering a human gene into a bacterial plasmid is an example of:

genetic engineering

what is the human genome project?

a research initiative aimed at mapping and understanding all the genes of the human genome

T/F most members of a species show differences or variations:

True

what type of evidence is the best indicator of how closely two species are related?

DNA sequence, amino acid sequences and similarities

susie is talal

genetic trats

phenotypes represent:

physical traits

the genotype ss is

homozygous recessive

the genotype TT is

homoygous dominant

the phenotype tall could be represented by what genotypes:

TT or Tt

the phenotype brown eyes could be represented by what genotypes

BB or Bb

the genotype Tt is

heterozygous

the genotype Ss is

heterozygous

the phenotype blue eyes could be represented by what genotype

bb

the phenotype for freckles could be represented by what genotypes

Ff or FF

Bb is

heterozygous dominant

TT

homozygous dominant

Tt

heterozygous dominant

bb

homozygous recessive

Ss

heteozygous dominant

Ff

heterozygous dominant

tt

homozygous recessive

on a pedigree, a square represents:

male

on a pedigree, a circle represents:

female

an unshaded circle or square represents a

individual without a trait

a shaded circle or square represents a

individual with the trait